Motor jitter issue with propeller

ArduCopter
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1

I have a Tarot 650 Sport Quadcopter UAV. The UAV is equipped with a Hex Cube Black flight controller, RFD868 modules.

I have done my motor ESC calibration and without Propeller they are working fine with RC. During motor test they also work fine with Propeller.

But when i attach the propeller to the motor they behave strange. Jitter and get struck.

Here is a video of motor test: 24-04-17 11-58-12 6214.mov - Google Drive

I had a crash few days ago, before that i never had that issue but now i am facing the same issue with all my 4 motors. Any idea what’s causing this behaviour?

PS: The jitter only happen at the start after the Propeller start rotating i never had that issue.

2

That looks like bad motor wire connections between motors and ESCs, or maybe even a motor mounting screw is protruding through to the motor windings.

3

All 4 motors are behaving the same, with propellers, without propellers they are fine.

4

I would work methodically: check the screws that secure the motors to the mounts, follow the motor wires back to the ESCs. Check the power distribution and battery connector.

Maybe supply the .bin log of the last successful flight, or if this is still being assembled and tested then set LOG_DISARMED,1 to generate a log with motor tests.
Then set LOG_DISARMED,0 when you’ve gathered enough data.
Upload the .bin log to a filesharing service and supply a link to it.

What ESCs do you have?

5

Here are the flight logs: test - Google Drive

The motor Stuttering only happens during first few secounds after that it start rotating fine. I tried to increase the throtle and check if the dorne can fly. However the drone was tilting toward one direction.

6

Check the MOT_SPIN_MIN and MOT_SPIN_ARM. They are usually only a few points different, but in this case they are very far apart. If a motor is jittering when you first arm but is working when you throttle up then increase the MOT_SPIN_ARM value. Use the motor test function in mission planner to verify the values.

I only looked at one log (just post one log, people won’t look at a bunch), and I noticed before the throttle went up the quad was sitting with a -10 degree roll so of course as the drone powered up it’s trying to correct the roll to level. If the drone was sitting flat then make sure the IMU calibration is correct.

The most common reason for this problem is the motor direction. Make sure that you have all your motors spinning the proper direction.

7

Maybe unplug the Cube from its carrier board and and reseat it.
Also unplug/replug all connectors.

8

Still having the same issue, i reset the flight controller, unplug/replug all connectors even replaced flight controller. Still facing the same issue.

9

I couldnt see anything specific causing the issue in that last log.
You could try these to see if it helps:

ATC_INPUT_TC,0.2
ATC_RAT_PIT_D,0.0048
ATC_RAT_PIT_I,0.12
ATC_RAT_PIT_P,0.12
ATC_RAT_RLL_D,0.0048
ATC_RAT_RLL_I,0.12
ATC_RAT_RLL_P,0.12
INS_ACCEL_FILTER,10
MOT_THST_EXPO,0.65

and you might as well put in these now for the harmonic notch filter, they wont hurt:

INS_HNTCH_ENABLE,1  // write this then refresh params to see the rest
INS_HNTCH_MODE,1
INS_HNTCH_BW,30
INS_HNTCH_FREQ,65
INS_HNTCH_FM_RAT,0.7
INS_HNTCH_HMNCS,3
INS_HNTCH_REF,0.17
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,4
10

I did the following changes you recommended and here are the motor test logs that i have done.

Link: 2024-04-23 14-45-21.bin - Google Drive

For motor test, the frame type is QUAD X, Motor 1 (CCW),2 (CCW), 3(CW) are tested with Propellers, Motor 4 (CW) had a propeller mounted on it.

11

I cant see anything wrong at all in that log since it’s just motor tests. Some of your previous tests were in stabilise mode, so you would need to try that again to tell if the issue still exists.